Acoustic Evoked Activity in the Brain in Sharks
Averaged evoked potentials (AEP’s) were recorded in the medulla, cerebellum, mesencephalon and telencephalon of several species of carcharhinid and triakid sharks, in the anesthetized animal with microelectrodes in the exposed brain and in the unanesthetized animal with implanted electrodes.
A preparation is described for recording from implanted electrodes with the unanesthetized shark suspended in the water by rubber bands, subject to air- or water-borne acoustic stimuli, or electric fields or photic stimuli.
AEP’s were found in each of the levels named above, to acoustic as well as to electric and photic stimuli. The responsive loci are discrete and small. The loci of best response are distinct for each of these three modalities. Anatomical localizations are given to within about one tenth of a neuromere but rarely to the microscopic level.
The form, latencies and recovery times of AEP’s are given for the several levels and modalities. No interaction occurred between modalities at least with brief stimuli.
The best acoustic stimulus for AEP amplitude is a “click” with a resonance of a few hundred Hz. The best tone stimulus is a rapidly rising burst of about 300 Hz. This value may be a function of size of animal, species, and electrode position. The lowest sound pressure threshold observed was —8 dB re I µbar near the shark’s head (=66 dB SPL). to a click delivered to the water surface. We do not know the velocity-wave amplitude, although it is believed to be the more relevant quantity.
Acoustic AEP’s were markedly suppressed by background white noise or tones — best at about 100 Hz.
When sound was delivered very locally the largest AEP occurred if the sound source was directly over the parietal fossa in the dorsal midline of the head. When sound was delivered at a distance, from a larger speaker, experimental occlusion of the parietal fossa usually suppressed the acoustic AEP. We interpret this to support the view that the fossa is an important portal for sound.
In two experiments bilateral section of the VIIIth nerve twig to the macula neglecta, together with some incidental damage to the sacculus greatly reduced the acoustic AEP. This supports the view that the macula neglecta is an important concentration of acoustic receptors but does not definitely confirm that proposal. The evidence argues against any substantial role of the lateral line in these species in response to acoustic stimuli at low amplitudes.
KeywordsLateral Line Sound Source Acoustic Stimulus Tone Burst Reef Shark
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- Banner, A. Evidence of sensitivity to acoustic displacements in the lemon shark,;Vegaprion brerirostris (Poey). In: Lateral line detectors. Cahn, P.H.(ed.), pp. 265–273. Bloomington, Indiana: Indiana University Press 1967Google Scholar
- Banner, A.: Use of sound in predation by young lemon sharks, Negaprian brerirostris (Poey). Bull. Marine Sci. 22, 251. 283 (1972)Google Scholar
- Bennett, M.V.L.: Electroreception. In: Fish physiology, V. Hoar, W.S., Randall, D.J. (eds.). New York: Academic Press 1971Google Scholar
- Bullock, T.H.: Problems in the comparative study of brain waves. Yale J. Biol. Med. 17, 657–679 (1945)Google Scholar
- Bullock, T.H.: Comparisons between vertebrates and invertebrates in nervous organization. In: The neurosciences, Third study program. Schmitt, F.O., Worden, F.W. et al. (eds.), pp. 343–346. Cambridge. Mass.: M.I.T. Press 1974Google Scholar
- Bullock, T.N.: Processing of ampullary input in the brain: Comparison of sensitivity and evoked responses among elasmobranch and siluriform fishes. J. Physiol. (Paris) (in press) (1978)Google Scholar
- Corwin. J.T.: Morphology of the macula neglecta in sharks of the genus Carsharhinus. J. Morph. 152. 341. 362 (1977)Google Scholar
- Corwin, J.T.: The relation of inner ear structure of feeding behavior in sharks and rays. Scanning Electron Microscopy/1978 v. 11, 1105–1112 (1978)Google Scholar
- Davies, D.H., Lochner. J.P.A., Smith. E.D.: Preliminary investigations on the hearing of sharks. S. African Assoc. Marine Biol. Res., Oceanog. Res. Inst., Invest. Rep. (7), 10 pp. (1963)Google Scholar
- Ebbesson, SO.E.. Northcutt, R.G.: Neurology of anamniotic vertebrates. In: Evolution of brain and behavior in vertebrates. Masterton, R.B., Bitterman, M.E.. Campbell. C.B.G., Holton, N. (eds.), pp. 115 146.Google Scholar
- Hillsdale, N.J.: Lawrence Erlbaum Associates 1976Google Scholar
- Fay. R.R.: Coding of information in single auditory-nerve fibers of the goldfish. J. Acoust. Soc. Am. 63, 136 146 (1978)Google Scholar
- Fay. R.R.. Kendall, J.I., Popper, A.N., Tester.. A.L.: Vibration detection by the macula neglecta of sharks. Comp. Biochem. Physiol. 47A, 1235 1240 11974 )Google Scholar
- Harris, G.G., van Bergeijk, W.A.: Evidence that the lateral line organ responds to near-field displacements of sound sources in water. J. Acoust. Sc. Am. 34, 1831 1841 119621Google Scholar
- Kalmijn. A.J.: The detection of electric fields from inanimate and animate sources other than electric fields. In: Handbook of sensory physiology, 1113s Electroreceptors and other specialized receptors in lower vertebrates. Fessard, A. (ed.). pp. 147–200. Berlin. Heidelberg. New York: Springer 1974Google Scholar
- Lowenstein, O.: The labyrinth. In Fish physiology, V. Hoar, W.S.. Randall, D.J. (eds). pp. 207–240. New York: Academic Press 1971Google Scholar
- Lowenstein, O., Roberts. T.D.M.: The localization and analysis of the responses to vibration from the isolated elasmobranch labyrinth. A contribution to the problem of the evolution of hearing in vertebrates. J. Physiol. (Lond.) 114. 471–489 (1951)Google Scholar
- Murray. R.W.: The ampullae of Lorenzini. In: Handbook of sensory physiology. 111)3. Fessard. A. (ed.), pp. 125–146. Berlin, Heidelberg, New York: Springer 1974Google Scholar
- Myrberg. A.A.,Jr., Ha, Si. Walewsky, S.. Banbury. J.C.: Effectiveness of acoustic signals in attracting epipelagic sharks to an underwater sound source. Bull. Marine Sci. 22, 926–949 (1972)Google Scholar
- Myrberg. A.A., Gordon. C.R., Klimley, A.P.: Attraction of free ranging sharks by low frequency sound, with comments on its biological significance. In: Sound reception in fish. Schuijf. A.. Hawkins, A.D. (eds.), pp. 205–228. Amsterdam: Elsevier 1976Google Scholar
- Nelson, D.R.: Hearing threshods, frequency discrimination and acoustic orientation in the lemon shark,.Vegaprion hrerirnstris (Poev). Bull. Marine Sci. 17, 741,-768 (1967)Google Scholar
- Nelson. D.R.. Johnson, R.H.: Some recent observations on acoustic attraction of Pacific reef sharks. In: Sound reception in fish. Schuijf, A.. Hawkins, A.D. (eds.). pp. 229–239. Amsterdam: Elsevier 1976Google Scholar
- Northcutt, R.G.: Elasmobranch central nervous system organizalion and its possible evolutionary significance. Am. Zool. 17, 411–429 (1977)Google Scholar
- Northcutt. R.G.: Brain organization in the cartilaginous fishes. In: Sensory biology of sharks. skates and rays. Hodgson, E.. Mathewson, R.F. (eds.). Washington. DC: U.S. Govt. Printing Office 1978Google Scholar
- Obara, B.: The perception of sound in small hammerhead sharks, Sphrrna leuini. M.S. Thesis. University of Hawaii 1962Google Scholar
- Parker, G-H.: The sense of hearing in the dogfish. Science 29, 428 (1909)Google Scholar
- Parvulescu. A.: Acoustics of small tanks. In: Marine bio-acoustics, Vol. 2. Tavolga. W.N. led.), pp. 1–13. Oxford: Pergamon Press 1967Google Scholar
- Popper, A.N., Fay, R.R.: Structure and function of the elasmobranch auditory system. Am. Zool. 17, 443–452 (1977)Google Scholar
- Tavolga. W.N.: Mechanisms for directional hearing in the sea catfish (Arius %eli.$). J. Exp. Biol. 67. 97–115 (1977)Google Scholar
- Tester, A.L., Kendall, J.I., Milisen, W.B.: Morphology of the ear of the shark genus Carcharhinus with particular reference to the macula neglecta. Pacif. Sci. 26. 264–274 (1972)Google Scholar
- van Bergeijk, W.A.: Directional and nondirectional hearing in fish. In: Marine bio-acoustics, Vol. I. Tavolga. W.N. (ed.), pp. 281–299. New York: Pergamon Press 1964Google Scholar
- Wisby, W.J., Richard, J. D., Nelson, D.R., Gruber. S.H.: Sound perception in elasmobranchs. In: Marine bio-acoustics. Vol. I. Tavolga, W.N. (ed.), pp. 255–268. New York: Pergamon Press 1964Google Scholar